1. – 1 – Data ConvertersDiscrete-Time Signal ProcessingProfessor Y. Chiu EECT 7327Fall 2014 Discrete-Time Signal Processing (A Review)

2. Sampling – 2 – Data ConvertersDiscrete-Time Signal ProcessingProfessor Y. Chiu EECT 7327Fall 2014 CT DT

3. Zero-Order Hold (ZOH) – 3 – Data ConvertersDiscrete-Time Signal ProcessingProfessor Y. Chiu EECT 7327Fall 2014

4. Sampling – 4 – Data ConvertersDiscrete-Time Signal ProcessingProfessor Y. Chiu EECT 7327Fall 2014 Impulse train

5. Sampling – 5 – Data ConvertersDiscrete-Time Signal ProcessingProfessor Y. Chiu EECT 7327Fall 2014 δ(t-nT)

6. Spectrum of Sampled Signal (Ω s >2Ω N ) – 6 – Data ConvertersDiscrete-Time Signal ProcessingProfessor Y. Chiu EECT 7327Fall 2014 The spectrum of the sampled signal is periodic in Ω s =2π/T.

7. Spectrum of Sampled Signal (Ω s <2Ω N ) – 7 – Data ConvertersDiscrete-Time Signal ProcessingProfessor Y. Chiu EECT 7327Fall 2014 Aliasing (folding) results in irreversible signal distortion. Can only be avoided by using sufficiently high sample rate, or band- limit the input signal with a coarse, continuous-time filter – AAF.

8. Reconstruction Filter (Nyquist) – 8 – Data ConvertersDiscrete-Time Signal ProcessingProfessor Y. Chiu EECT 7327Fall 2014 Reconstruction filter = “smoothing” filter = “interpolation” filter